1. Field of the Invention
The present invention relates to a vehicle wheel for a pneumatic tire. The wheel comprises a one-piece wheel rim on which can be mounted the pneumatic tire, which has a tread strip, two sidewalls, and a carcass, in addition to two tire beads which are laterally spaced from one another and contain substantially inextensible bead bores; the wheel rim has two rim shoulders, which are laterally spaced from one another and extend outwardly into a respective rim edge or into a respective rim flange, and a radially recessed rim base; the wheel also comprises an emergency operation support member which is disposed in the recessed rim base and has a supporting surface which is located radially outwardly of the rim flange and has a width which corresponds approximately to that of the rim base.
2. Description of Prior Art
In such vehicle wheel and pneumatic tire assemblies, the tire beads are held in position by a rim flange to prevent them from slipping laterally from the wheel rim. In an emergency operation, the deflated tire is supported by an emergency operation support member. However, the known vehicle wheels having an emergency operation support member are disadvantageous for a number of reasons. The drop well, which is provided as a means for simplifying tire mounting, cannot fulfill this function when essential elements of the emergency operation support member fill this drop well. With the known arrangement and construction, the emergency operation support member is suitable for absorbing load during emergency operation, but it does not compensate for the dangerous operational condition which results from slight losses of compressed air. This applies, for example, when travelling around curves at excessively high speed. The emergency operation support member therefore does not have a means for ensuring safety and preventing release from the wheel rim when the tire beads of a tire which has little air therein initially slide into the drop well and can then slip off the vehicle wheel over the rim flange, thereby ruining the pneumatic tire.
Known, multiple-part wheel rims, which are capable of being assembled during tire mounting, have a closed drop well which serves to prevent the release of beads. However, from the point of view of construction and operation, the multiple-part rims are complicated.
The present invention is based on the recognition that a vehicle wheel and tire assembly of the type described should comprise a tire of conventional, standard construction, and a one-piece wheel rim, likewise of conventional, standard construction; the tire should also be easy to mount, and should reliably fulfill normal, everyday travel operations. In addition, the wheel should have an emergency operation support member which has a simple construction and reliably copes with the emergency operation situation. However, this vehicle wheel should also be capable of ensuring safe travel in the event of a loss in compressed air prior to emergency operation and during emergency travel with a deflated tire, without the need to provide additional means therefor.
In this respect, the invention is concerned with improving the emergency operation support member or, respectively, with an integrated component part comprising wheel rim and emergency operation support member.
The technical object of the present invention is to develop a vehicle wheel of the aforementioned general type in such a way that the emergency operation support member is provided with a means for preventing the tire bead from being released from the one-piece wheel rim, and with a means for accommodating the tire bead during emergency operation, without adversely affecting, rather fully maintaining, the simplified mounting of the tire by means of a rim drop well, and the advantageous support of the tire during emergency operation.